1.Transition to a Primary Care–Centered Healthcare System: A Structural Reform for Korean Healthcare
Serng Bai PAK ; Sang-Hyun LEE ; Kyung-Hee CHO ; Juhwan OH ; Sang-il LEE ; Kunhee PARK ; Jae-Heon KANG ; Seung-Won OH ; Hee Gyung KANG ; Mihwa YOO
Korean Journal of Family Practice 2026;16(1):33-41
Korea’s healthcare system is at a critical juncture as rapid population aging, rising chronic disease burdens, and fragmented care expose the limits of a hospital-centered, fee-for-service model. Although policy discussions have long emphasized strengthening primary care and introducing a “family doctor” system, past reforms have focused mainly on expanding services or redefining professional roles, without establishing clear accountability, care continuity, or aligned payment mechanisms. Consequently, primary care remains weak and responsibility for comprehensive patient management is diffuse. This article argues that meaningful reform requires redefining the primary physician as an accountable manager of longitudinal, coordinated care within an integrated delivery and payment framework. Drawing on experiences from the United States, the United Kingdom, and several European countries, it identifies common features of successful primary care–oriented systems, including patient registration, team-based care, risk-adjusted payment, and explicit outcome accountability. Based on these insights, the authors propose a Korean primary physician model tailored to solo and small-group practices while fostering regional collaboration. Core elements include voluntary patient registration, multidisciplinary primary care teams, risk-stratified care management, regional care networks, and a mixed payment model combining per-member-per-month payments, shared savings, and performance-based incentives. The article emphasizes phased pilot testing focused on operational feasibility. Ultimately, transitioning to a primary care–centered system is presented as a strategic necessity for sustainability and improved care continuity.
2.Stress Accelerates Depressive-Like Behaviors through Increase of Notch2 Expression in N141I Mutation Presenilin-2 Transgenic Mice
Seung Sik YOO ; Sun Mi GU ; Kyung Tak NAM ; Jeong Soon CHOI ; Yong Sun LEE ; In Jun YEO ; Ji Eun YU ; Sanghyeon KIM ; Dong Won LEE ; Hyeon Joo HAM ; Ju Young CHANG ; Jaesuk YUN ; Dong Ju SON ; Sang-Bae HAN ; Jin Tae HONG
Biomolecules & Therapeutics 2026;34(3):544-555
Alzheimer’s disease (AD) is characterized by progressive cognitive deterioration and significant depression. However, the mechanisms linking depression to AD pathology remain unclear. Here, we investigated whether Notch2 signaling mediates depressionlike behaviors in presenilin-2 (PS2) N141I mutant mice, an early-onset AD model. PS2 wild-type (WT) and mutant (MT) mice aged 12-15 months were subjected to unpredictable chronic mild stress (UCMS) for 4 weeks, followed by sucrose preference, tail-hanging, and forced swimming tests. Behavioral assessments showed that UCMS exacerbated anhedonia and immobility only in PS2 MT mice. Molecular analysis revealed concomitant increases in plasma corticosterone, hippocampal γ-secretase activity, and Notch2 expression, and elevated total and phosphorylated glucocorticoid receptor levels in PS2 MT-UCMS mice. Gene expression profiling of human hippocampal datasets confirmed upregulation of NOTCH2 in Alzheimer’s disease and depression.Pharmacological inhibition of γ-secretase and Notch signaling with DAPT normalizes depressive behavior, reduces corticosterone release, attenuates GR phosphorylation, and inhibits Notch2 signaling in PS2 MT mice. These findings identify Notch2 as a pivotal mediator linking chronic stress to molecular changes associated with depression and AD, and suggest that targeting Notch2 signaling may provide therapeutic benefits for comorbid mood and neurodegenerative disorders.
3.Associated factors of osteoporosis and the impact of osteoporosis on all-cause mortality in incident hemodialysis older patients
Seunghye LEE ; Yoomee KANG ; Yu Ah HONG ; Sung Joon SHIN ; Soon Hyo KWON ; Sungjin CHUNG ; Young Youl HYUN ; Sang Heon SONG ; Jae Won YANG ; Won Min HWANG ; Jang-Hee CHO ; Kyung Don YOO ; In O SUN ; Gang-Jee KO ; Byung Chul YU ; Hyunsuk KIM ; Woo Yeong PARK ; Tae Won LEE ; Dong Jun PARK ; Eunjin BAE ;
Kidney Research and Clinical Practice 2026;45(1):110-119
Background:
With the aging population and advancements in medical care worldwide, the number of older patients with end-stage kidney disease continues to rise. This study aimed to identify factors associated with osteoporosis and osteopenia in older patients undergoing incident hemodialysis and assess their impact on mortality.
Methods:
We analyzed a large multicenter retrospective cohort of patients aged ≥70 years undergoing incident hemodialysis to identify factors associated with osteoporosis using logistic regression analysis and to assess the association of death with osteoporosis and osteopenia using Cox multivariable analysis.
Results:
Among 710 patients, 39.0% and 19.6% had osteoporosis and osteopenia, respectively. Osteoporosis was significantly associated with female sex, a history of fractures, and the absence of phosphate binder use. During a median follow-up of 36.8 months, 348 participants (58.8%) died. Mortality rates were the highest in the osteoporosis group (79.8%), followed by the osteopenia (77.2%) and normal bone mineral density (BMD) groups (35.2%). Cox regression analysis revealed that even after adjusting for covariates, the osteoporosis group was significantly associated with a higher mortality risk than the normal BMD group. Osteoporosis at the start of hemodialysis was significantly associated with higher mortality.
Conclusion
We should consider the importance of bone health in patients undergoing incident hemodialysis and pay attention to the use of phosphate binders and fracture prevention.
4.Impact of obesity on renal function in elderly Korean adults: a national population-based cohort study
Jihyun YANG ; Hui Seung LEE ; Chi-Yeon LIM ; Hyunsuk KIM ; Sungjin CHUNG ; Soon Hyo KWON ; Jang-Hee CHO ; Kyung Don YOO ; Woo Yeong PARK ; In O SUN ; Byung Chul YU ; Gang-Jee KO ; Jae Won YANG ; Won Min HWANG ; Sang Heon SONG ; Sung Joon SHIN ; Yu Ah HONG ; Eunjin BAE ; Young Youl HYUN
Kidney Research and Clinical Practice 2026;45(1):65-76
Background:
Obesity is a well-known risk factor for chronic kidney disease and its progression. However, the impact of obesity on the renal function of the elderly population is uncertain. We investigated the association between obesity and renal outcomes in the elderly.
Methods:
We analyzed 130,504 participants from the Korean National Health Insurance Service-Senior cohort. Obesity was classified according to body mass index (BMI), sex-specific waist circumference (WC), and the presence of metabolic syndrome. The primary outcome was renal function decline, defined as a decline in the estimated glomerular filtration rate (eGFR) of at least 50% from baseline or new-onset end-stage renal disease.
Results:
During a follow-up period of 559,531.1 person-years (median, 4.3 years), 2,486 participants (19.0%; incidence rate of 4.44 per 1,000 person-years) showed renal function decline. A multivariate Cox proportional hazards model revealed that BMI/WC was not associated with renal function decline. However, the group with metabolic syndrome had a significantly increased risk of renal function decline compared to the group without metabolic syndrome (adjusted hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.13–1.36). Compared with the non-metabolic syndrome group, the adjusted HRs (95% CI) for participants with one through five components were 0.96 (0.84–1.11), 1.10 (0.96–1.27), 1.24 (1.06–1.45), 1.37 (1.12–1.66), and 1.99 (1.42–2.79), respectively (p for trend < 0.001).
Conclusion
In elderly Korean adults, metabolic syndrome and the number of its components were associated with a higher risk of renal function decline, but BMI or WC was not significant.
5.Cardiac 123I-Meta-Iodobenzylguanidine Imaging as a Biomarker for Body-First Parkinson’s Disease: Linking Peripheral α-Synuclein to Clinical Subtyping
Dong-Woo RYU ; Sang-Won YOO ; Yoonsang OH ; Joong-Seok KIM
Journal of Movement Disorders 2026;19(1):1-10
Recent neuropathological and imaging studies support the concept of “brain-first vs. body-first” Parkinson’s disease (PD), which is based on the α-synuclein origin site and connectome model. The body-first phenotype is characterized by early involvement of the peripheral autonomic nervous system, particularly the cardiac sympathetic nerves and enteric nerves. 123I-meta-iodobenzylguanidine (123I-MIBG) myocardial scintigraphy is a well-established method for evaluating cardiac sympathetic innervation. This review explores the potential of 123I-MIBG scintigraphy as a biomarker to differentiate the body-first phenotype from the brain-first phenotype. Reduced 123I-MIBG uptake has been observed in idiopathic rapid eye movement (REM) sleep behavior disorder, pure autonomic failure, and incidental Lewy body disease—conditions strongly associated with prodromal or early-stage PD. Postmortem and biopsy evidence indicates α-synuclein accumulation in cardiac nerves and other peripheral sites, which is consistent with bottom-up progression. α-Synuclein seed amplification assays further corroborate the association between the peripheral α-synuclein burden and reduced 123I-MIBG uptake. While 123I-MIBG myocardial scintigraphy is a promising tool, its limitations include cost, limited availability, and potential confounding from underlying cardiac conditions. Nonetheless, early detection of cardiac sympathetic denervation via 123I-MIBG imaging may enhance diagnosis, support subtype classification, and improve the understanding of PD pathogenesis.
6.Implant-assisted removable partial denture restoration in a patient with mandibular single tooth: a case report
Yoo-Cheung CHOI ; Ji-Won BANG ; Sung-Yong KIM ; Hee-Won JANG ; Yong-Sang LEE ; Keun-Woo LEE ; Joo-Hyuk BANG
The Journal of Korean Academy of Prosthodontics 2026;64(1):104-112
With a solitary remaining tooth in the mandible, restoration with a conventional removable partial denture is often associated with insufficient retention, support, and stability, as well as excessive stress concentration on the remaining tooth, leading to an unfavorable prognosis. Recently, treatment plans involving the placement of a small number of strategically positioned implants to fabricate removable partial dentures have been adopted to overcome these limitations.The use of implant surveyed crowns is considered to offer superior long-term outcomes compared with implant attachments. This report describes the restoration of a partially edentulous mandible with a single remaining tooth using an implant-assisted removable partial denture assisted by a surveyed fixed partial denture following bilateral posterior implant placement, achieving favorable clinical results.
7.Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Part II. Follow-up Surveillance after Initial Treatment 2026
Eun Kyung LEE ; Seung Heon KANG ; Bon Seok KOO ; Mijin KIM ; Min Joo KIM ; Bo Hyun KIM ; Ji Won KIM ; Dong Gyu NA ; Sohyun PARK ; Ji-In BANG ; Kyorim BACK ; Youngduk SEO ; Young-Ik SON ; Young Shin SONG ; Dong Yeob SHIN ; Jong-Hyuk AHN ; Hwa Young AHN ; So Won OH ; Ho-Ryun WON ; Won Sang YOO ; Min Kyoung LEE ; Sang-Woo LEE ; Jeongmin LEE ; Ji Ye LEE ; Dong-Jun LIM ; Ki-Wook CHUNG ; Ari CHONG ; Jin Hyang JUNG ; Sun Wook CHO ; Yoon Young CHO ; Chae Moon HONG ; Young Joo PARK ;
International Journal of Thyroidology 2026;19(1):1-40
In patients with differentiated thyroid cancer (DTC), initial recurrence risk stratification based on clinical, histopathological, and perioperative data remains the key determinant for guiding management strategies during the first 1-2 years post-treatment. However, the adoption of ongoing risk stratification (ORS), which dynamically reassesses risk by integrating longitudinal clinical data and treatment response, enables more precise long-term prognostic assessment and facilitates highly individualized management. Building upon recent guidelines, the 2026 KTA guideline has been further refined by incorporating robust evidence from large-scale national cohorts and comprehensive systematic reviews. These updated recommendations outline contemporary concepts of ORS, risk-adapted TSH suppression targets, optimized surveillance modalities for recurrence detection, and disease-specific long-term follow-up strategies. Reflecting the paradigm shift toward de-escalated treatment, this revision integrates evolved perspectives on TSH suppression intensity, the clinical interpretation of thyroglobulin levels, and tailored follow-up intervals. These evidence-based recommendations aim to minimize unnecessary treatment and excessive surveillance in the large proportion of patients with excellent prognosis after initial therapy, while ensuring that each patient receives appropriately tailored and effective long-term management.
8.Risk of Osteoporotic Fractures among Patients with Thyroid Cancer: A Nationwide Population-Based Cohort Study
Eu Jeong KU ; Won Sang YOO ; Yu Been HWANG ; Subin JANG ; Jooyoung LEE ; Shinje MOON ; Eun Kyung LEE ; Hwa Young AHN
Endocrinology and Metabolism 2025;40(2):225-235
Background:
The associations between thyroid cancer and skeletal outcomes have not been thoroughly investigated. We aimed to investigate the risk of osteoporotic fractures in patients with thyroid cancer compared to that in a matched control group.
Methods:
This retrospective cohort study included 2,514 patients with thyroid cancer and 75,420 matched controls from the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC, 2006–2019). The rates of osteoporotic fractures were analyzed, and associations with the levothyroxine dose were evaluated.
Results:
Patients with thyroid cancer had a significantly lower risk of fracture than did the control group (hazard ratio [HR], 0.81; 95% confidence interval [CI], 0.69 to 0.94; P=0.006). Patients diagnosed with thyroid cancer after the age of 50 years (older cancer group) had a significantly lower risk of fracture than did those in the control group (HR, 0.72; 95% CI, 0.6 to 0.85; P<0.001), especially those diagnosed with spinal fractures (HR, 0.66; 95% CI, 0.51 to 0.85; P=0.001). Patients in the older cancer group started osteoporosis treatment earlier than did those in the control group (65.5±7.5 years vs. 67.3±7.6 years, P<0.001). Additionally, a lower dose of levothyroxine was associated with a reduced risk of fractures.
Conclusion
In the clinical setting, the risk of fracture in women diagnosed with thyroid cancer after the age of 50 years was lower than that in the control group, which was caused by more proactive osteoporosis treatment in postmenopausal women with thyroid cancer.
9.Stress Accelerates Depressive-Like Behavior through Increase of SPNS2 Expression in Tg2576 Mice
Seung Sik YOO ; Yuri KIM ; Dong Won LEE ; Hyeon Joo HAM ; Jung Ho PARK ; In Jun YEO ; Ju Young CHANG ; Jaesuk YUN ; Dong Ju SON ; Sang-Bae HAN ; Jin Tae HONG
Biomolecules & Therapeutics 2025;33(3):417-428
To investigate the relationship between depression and AD, water avoidance stress (WAS) was induced for 10 days in both Tg2576 mice and wild-type (WT) mice. After WAS, memory function and depressive-like behavior were investigated in Tg2576 mice. Tg2576 WAS mice exhibited more depressive-like behaviors than WT WAS and Tg2576 control (CON) mice. Strikingly, Tg2576 CON mice showed more depressive-like behaviors than WT mice. Moreover, corticosterone and phospho-glucocorticoid receptor (p-GR) levels were also higher in Tg2576 WAS mice in comparison to Tg2576 CON mice. Spinster homologue 2 (SPNS2) is a member of non-ATP-dependent transporter. The role of SPNS2 was widely known as a sphingosine-1-phosphate (S1P) transporter, which export intracellular S1P from cells. Using GEO database to analyze SPNS2 gene expression changes in patients with AD and depression, we show that SPNS2 gene expression correlates with AD and depression. Interestingly, Tg2576 WAS mice displayed significantly increased levels of SPNS2 w1hen compared to Tg2576 CON counterparts. SPNS2 levels were also higher in Tg2576 CON mice in comparison with WT CON mice. Remarkably, we found a decrease in S1P brain levels and an increase in S1P serum levels of Tg2576 WAS mice in comparison with Tg2576 CON mice. Accordingly, WAS induced group further decreased S1P levels in the brains. However, the level in the serum further increased in comparison with non-induced group. Therefore, these results suggest that AD and depression could be associated, and that Tg2576 transgenic mice are more susceptible to stress-induced depression through the release of S1P by SPNS2 up-regulation.
10.The Effect of Hematopoietic Stem Cell Transplantation on Treatment Outcome in Children with Acute Lymphoblastic Leukemia
Hee Young JU ; Na Hee LEE ; Eun Sang YI ; Young Bae CHOI ; So Jin KIM ; Ju Kyung HYUN ; Hee Won CHO ; Jae Kyung LEE ; Ji Won LEE ; Ki Woong SUNG ; Hong Hoe KOO ; Keon Hee YOO
Cancer Research and Treatment 2025;57(1):240-249
Purpose:
Hematopoietic stem cell transplantation (HSCT) has been an important method of treatment in the advance of pediatric acute lymphoblastic leukemia (ALL). The indications for HSCT are evolving and require updated establishment. In this study, we aimed to investigate the efficacy of HSCT on the treatment outcome of pediatric ALL, considering the indications for HSCT and subgroups.
Materials and Methods:
A retrospective analysis was conducted on ALL patients diagnosed and treated at a single center. Risk groups were categorized based on age at diagnosis, initial white blood cell count, disease lineage (B/T), and cytogenetic study results. Data on the patients’ disease status at HSCT and indications of HSCT were collected. Indications for HSCT were categorized as upfront HSCT at 1st complete remission, relapse, and refractory disease.
Results:
Among the 549 screened patients, a total of 418 patients were included in the study; B-cell ALL (n=379) and T-cell ALL (T-ALL) (n=39). HSCT was conducted on a total of 106 patients (25.4%), with a higher frequency as upfront HSCT in higher-risk groups and specific cytogenetics. The overall survival (OS) was significantly better when done upfront than in relapsed or refractory state in T-ALL patients (p=0.002). The KMT2A-rearranged ALL patients showed superior event-free survival (p=0.002) and OS (p=0.022) when HSCT was done as upfront treatment.
Conclusion
HSCT had a substantial positive effect in a specific subset of pediatric ALL. In particular, frontline HSCT for T-ALL and KMT2A-rearranged ALL offered a better prognosis than when HSCT was conducted in a relapsed or refractory setting.

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